3.1.11. Signaling

The Signal API shown in Figure 3.10 defines classes and interfaces for the modeling
of side-band signals such as, for example, interrupts. There are
two variants of these classes and interfaces:

the Signal one that permits components to indicate a signal
state change to other components and uses the signal_ prefix

the SignalState one that permits the other components
to passively query the current state of the signal and uses the signal_state_ prefix.

The
Signal API features immediate propagation of the signal state (no
update phase or time elapse) and does not require intermediate storage
of the signal state in a channel.

The Signal classes and interfaces features a STATE template
parameter.

Note

These Signal classes and interfaces are provided as part of
AMBA-PV as an alternative to using SystemC sc_signal<> for
side-band signal modeling at PV-level. The SystemC sc_signal<> is implemented
as a primitive channel using the request/update mechanism. This
introduces extra processes, resulting in extra delta cycles in the
simulation, and prevents immediate propagation of the signal state.

Figure 3.10. Signaling

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